The inventors of the present invention invented a small and thin electromagnetic pump, wherein a moving member made of a magnetic material is reciprocally moved in a cylinder of a stator, pump chambers are respectively formed between both end faces of the cylinder and both side faces of the moving member extended in the moving direction thereof, electromagnetic coils are fitted around periphery of the cylinder, a fluid is introduced into one of the pump chambers from outside via a first valve and discharged outside via a second valve by applying electricity to the electromagnetic coils, and the fluid is introduced into and discharged from the other pump chamber by the same manner (see Patent Document 1).
FIG. 7 shows partial sectional views of the moving member 101 and the stator 102. Note that, the cylinder section between the moving member 101 and the stator 102 is omitted. Magnetic fluxes generated from an N-pole of a magnet 103 of the moving member 101 form a magnetic circuit to an S-pole of the magnet 103 via an inner yoke 104a, an outer yoke 105 and an inner yoke 104b. By applying electricity to electromagnetic coils 106a and 106b, an electromagnetic force is applied to the electromagnetic coils 106a and 106b from the magnetic field, but the electromagnetic coils 106a and 106b are fixed to the stator 101 so that the moving member 102 is moved in the axial direction (in the vertical direction in FIG. 7) as a counteraction.
Patent Document 1; Japanese Pat. App. 20002-286188